Voice interactive device and voice interaction method

ABSTRACT

A voice interactive device that interacts with a user by voice, the device comprises a voice input unit that acquires and recognizes voice uttered by a user; a degree-of-intimacy calculating unit that calculates a degree of intimacy with the user; a response generating unit that generates a response to the recognized voice, based on the degree of intimacy; and a voice output unit that outputs the response by voice, wherein the degree-of-intimacy calculating unit calculates a degree of intimacy with the user based on a sum of a first intimacy value calculated based on a content of an utterance made by the user and a second intimacy value calculated, based on the number of previous interactions with the user.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a device which interacts with a personby voice.

Description of the Related Art

In recent years, robots which provide various kinds of information byinteracting with a person are being developed. In particular, manycommunication robots are being developed which process voice inputthrough a microphone and which returns a voice response to the input. Inaddition, attempts are being made to impart simulated emotions to arobot to enable the robot to interact in a more human-like manner.

For example, a robot described in Japanese Patent Application Laid-openNo. 2004-090109 is characterized in that a degree of intimacy iscalculated based on the number of interactions and a total time of theinteractions and that a response to a user is changed based on thecalculated degree of intimacy. In addition, a robot described inJapanese Patent Application Laid-open No. 2001-488779 is characterizedin that the robot determines a degree of intimacy based on contents ofan utterance made by a user to the robot and returns an appropriateresponse.

SUMMARY OF THE INVENTION

Generally, when a person communicates with another person, a degree ofintimacy with respect to the other person varies significantly dependingon how the two persons were previously in contact with each other.However, since interactive robots in conventional art only calculate adegree of intimacy based on limited elements, there is a problem ingenerating responses that are more human-like.

The present invention has been made in consideration of the problemdescribed above and an object thereof is to calculate a degree ofintimacy with higher accuracy in a voice interactive device whichinteracts with a person by voice.

The present invention in its one aspect provides a voice interactivedevice that interacts with a user by voice, the device comprising avoice input unit that acquires and recognizes voice uttered by a user; adegree-of-intimacy calculating unit that calculates a degree of intimacywith the user; a response generating unit that generates a response tothe recognized voice, based on the degree of intimacy; and a voiceoutput unit that outputs the response by voice, wherein thedegree-of-intimacy calculating unit calculates a degree of intimacy withthe user based on a sum of a first intimacy value calculated based on acontent of an utterance made by the user and a second intimacy valuecalculated, based on the number of previous interactions with the user.

A voice interactive device according to the present invention calculatesa first intimacy value based on contents of an utterance made by a userto the device and calculates a second intimacy value based on the numberof previous interactions with the user.

The first intimacy value may be calculated based solely on contents of alatest utterance or may be calculated based on contents of apreviously-made utterance. In addition, a value calculated based oncontents of a previously-made utterance may be updated using a valuecalculated based on contents of a latest utterance.

In addition, the second intimacy value is calculated based on the numberof interactions previously performed by a user with respect to thedevice. For example, the number of times interactions have beenperformed or a frequency of interactions in a prescribed period may beused. Alternatively, weighting may be performed using an elapsed timeafter an interaction.

According to the configuration described above, since a degree ofintimacy is calculated according to the two criteria of the contents ofinteractions and the frequency of interactions, a degree of intimacywhich is more human-Like can be calculated.

The voice interactive device according to the present invention mayfurther comprises a storage unit that stores the calculated degree ofintimacy, and when an utterance is received from the user, thedegree-of-intimacy calculating unit may calculate an amount of variationof the degree of intimacy attributable to the utterance and updates thefirst intimacy value and the second intimacy value.

While a degree of intimacy may be calculated every time an interactionis performed, a previously-calculated value may be stored to be updatedevery time an utterance is received from a user. In other words, amountsof variation may be respectively calculated with respect to the firstintimacy value and the second intimacy value and each amount ofvariation. may be updated.

As described above, by applying “an amount of variation of the degree ofintimacy attributable to a latest interaction” to a stored degree ofintimacy to calculate a latest degree of intimacy, an effect can beobtained in that the degree of intimacy gradually varies as moreinteractions are performed.

The voice interactive device according to the present invention mayfurther comprises a user identifying unit that identifies a user, andthe storage unit may store the degree of intimacy for each user.

For example, a user identifying unit may identify a user based on voiceor an image or may identify the user based on an input obtained from theuser. A voice print or the like may be used when the user is identifiedbased on voice, and a feature amount extracted from a facial image orthe like may be used when the user is identified based on an image. Inthis manner, by storing and using a degree of intimacy for each user,the degree of intimacy between the device and a user can be calculatedmore accurately.

Further, the degree-of-intimacy calculating unit may correct an amountof variation of the first intimacy value or the second intimacy value,based on an elapsed time since the last contact with the user.

In real communication, the longer the time from a last contact, thelower the degree of intimacy. In consideration thereof, a calculatedamount of variation of a degree of intimacy can be corrected based onthe time elapsed from a last contact made between a user and the device.For example, when the time elapsed from making a last contact is longer,the amount of variation of a degree of intimacy may be corrected to alarger extent in a negative direction. Accordingly, communication can beperformed in a more human-like manner.

The present invention in its another aspect provides an interactionsystem comprising a voice interactive device and an interactive server,the voice interactive device includes a voice input unit that acquiresvoice uttered by a user and that transmits the voice to the interactiveserver; and a voice output unit that acquires a response to the voicefrom the interactive server and that outputs the response by voice, andthe interactive server includes a voice recognition unit that recognizesthe voice uttered by the user; a degree-of-intimacy calculating unitthat calculates a degree of intimacy with the user; and a responsegenerating unit that generates a response to the recognized voice, basedon the degree of intimacy, and that transmits the response to the voiceinteractive device, wherein the degree-of-intimacy calculating unitcalculates a degree of intimacy with the user, based on a first intimacyvalue calculated based on a content of an utterance made by the user anda second intimacy value calculated based on the number of previousinteractions with the user.

Moreover, the present invention can be identified as a voice interactivedevice or an interaction system which includes at least a part of theunits described above. In addition, the present invention can also beidentified as a voice interaction method carried out by the voiceinteractive device or the interaction system. The processes and unitsdescribed above may be implemented in any combination thereof insofar astechnical contradictions do not arise.

The present invention is capable of calculating a degree of intimacywith higher accuracy in a voice interactive device which interacts witha person by voice.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system configuration diagram of a robot according to a firstembodiment;

FIG. 2 shows an example of a degree-of-intimacy table according to thefirst embodiment;

FIG. 3 is a flow chart of a process performed by a robot 10; FIG. 4 is asystem configuration diagram of an interaction system according to asecond embodiment; and

FIG. 5 is a system configuration diagram according to one embodiment.

DESCRIPTION OF THE EMBODIMENTS

(First Embodiment)

Hereinafter, a preferred embodiment of the present invention will bedescribed with reference to the drawings.

A. robot according to the present embodiment is a device which acquiresan utterance made by a user to perform voice recognition and whichinteracts with the user by generating a response sentence based on arecognition result and outputting the response sentence.

<System Configuration>

FIG. 1 is a system configuration diagram of a robot 10 according to thepresent embodiment.

The robot 10 has a function for acquiring voice from the outside, afunction for recognizing the acquired voice, a function for acquiring aresponse to the voice, and a function for outputting the response byvoice. While an example of the robot 10 is a communication robot, therobot 10 need not necessarily have a semblance of a character. Forexample, a general-purpose computer that can be built into a robot maysuffice,

The robot 10 is constituted by a voice input/output unit 11, a voicerecognition unit 12, a degree-of-intimacy calculating unit 13, aresponse generating unit 14, and a controlling unit 15.

The voice input/output unit 11 is a unit used to input and output voice.Specifically, voice is converted into an electrical signal (hereinafter,voice data) using a microphone 50. Acquired voice data is output to thevoice recognition unit 12 to be described later. In addition, the voiceinput/output unit 11 uses a speaker 52 to convert voice data transmittedfrom the controlling unit 15 into voice (see FIG. 5).

The voice recognition unit 12 is a unit which performs voice recognitionon the voice acquired by the voice input/output unit 11 and whichconverts the voice into a text. Voice recognition can be performed usingexisting techniques. For example, the voice recognition unit 12 storesacoustic models and a recognition dictionary and performs voicerecognition by comparing acquired voice data with an acoustic model toextract a feature and matching the extracted feature with therecognition dictionary. Recognition results are transmitted to thecontrolling unit 15.

The degree-of-intimacy calculating unit 13 is a unit which calculates adegree of intimacy between the robot 10 and a user. Thedegree-of-intimacy calculating unit 13 stores a value representing acurrent degree of intimacy for each user in a table format (adegree-of-intimacy table) and, when an utterance is received from auser, calculates a degree of intimacy based on contents of the utteranceand on the stored table. The calculated degree of intimacy istransmitted to the response generating unit 14 to be described later andused to generate a response. In addition, the degree-of-intimacycalculating unit 13 updates the degree-of-intimacy table using thecalculated degree of intimacy.

FIG. 9 shows an example of the degree-of-intimacy table stored by thedegree-of-intimacy calculating unit 13. The degree-of-intimacy tablerecords, together with a time and date of a last interaction between auser and the robot 10 and a coefficient, a degree of intimacy calculatedbased on contents of an utterance made by the user (hereinafter, a firstintimacy value) and a degree of intimacy calculated based on the numberof interactions between the user and the robot 10 (hereinafter, a secondintimacy value).

A method of calculating the first and second intimacy values and detailsof the time and date of a last interaction and the coefficient will bedescribed later.

The response generating unit 14 is a unit which generates a sentence (anuttered sentence) as a reply to a user based on a text output by thevoice recognition unit 12 (in other words, contents of an utterance madeby the user). For example, the response generating unit 14 may generatea response based on an interaction scenario (an interaction dictionary)stored in advance.

In addition, the response generating unit 14 generates a response byalso taking a degree of intimacy calculated by the degree-of-intimacycalculating unit 13 into consideration. Specifically, for example, aresponse is generated based on an input degree of intimacy such asgenerating a sentence in a courteous tone when the degree of intimacy islow and generating a sentence in a friendly tone when the degree ofintimacy increases Therefore, the response generating unit 14 may beprovided with an interaction scenario in accordance with the degree ofintimacy.

The response generated the response generating unit 14 is transmitted ina text format to the controlling unit 15 and subsequently output towardthe user by a synthesized voice.

The controlling unit 15 is a unit which con roll, as a whole, voiceinteraction performed by the robot 10. Specifically, the controllingunit 15 executes a function for detecting a presence of an interactionpartner (a user) and starting an interaction, a function for causingvoice recognition to be executed on an utterance by the user, a functionfor causing generation of a response sentence to be executed, a functionfor converting an acquired uttered sentence into voice data andoutputting the voice data via the voice input/output unit 11, and thelike.

The robot 10 can be configured as an information processing apparatusincluding a CPU 54 (see FIG. 5), a main storage apparatus, and anauxiliary storage apparatus. The respective units illustrated in FIG. 1function as a result of a program stored in the auxiliary storageapparatus being loaded onto the main storage apparatus and executed bythe CPU 54. Alternatively, all of or a part of the illustrated functionsmay be executed using exclusively designed circuits.

<Method of Calculating Degree of Intimacy>

Next, a method of calculating a degree of intimacy will be described.The calculation of a degree of intimacy is performed by thedegree-of-intimacy calculating unit 13 when the robot 10 receives anutterance from a user. An example will now be described in which, asshown in FIG. 2, a user has a first intimacy value (a degree of intimacybased on utterance contents) of 30 and a second intimacy value (a degreeof intimacy based on the number of interactions) of 20. A degree ofintimacy recorded in the degree-of-intimacy table is a degree ofintimacy as of the present moment (in other words, a degree of intimacycalculated when an interaction had been last performed).

(1) Acquire Amount of Variation in Degree of Intimacy Based on UtteranceContents

First, the degree-of-intimacy calculating unit 13 calculates an amountof variation of the first intimacy value (hereinafter, an amount ofvariation α) based on contents of an utterance made by the user. Theamount of variation α is a value representing how much the degree ofintimacy varies due to a latest utterance made by the user. Thecalculation of the amount of variation α can be performed by a methodsuch as that described below.

For example, the degree-of-intimacy calculating unit 13 performs amorphological analysis on a text acquired from the voice recognitionunit 12 and compares each of the obtained morphemes with adegree-of-intimacy dictionary stored in advance. The degree-of-intimacydictionary is a list of an increase or decrease amount of the degree ofintimacy defined for each keyword, and the amount of variation α of thefirst intimacy value represents a sum of the increase or decreaseamounts of the degree of intimacy corresponding to matching keywords.Moreover, a method of calculating an amount of variation is not limitedto the example described above as long as an amount of variation of thedegree of intimacy attributable to an utterance by the user can becalculated. In the present example, it is assumed. that a value of α=5has been obtained.

(2) Acquire Amount of Variation in Degree of Intimacy Based on ElapsedTime

Next, the degree-of-intimacy calculating unit 13 acquires an amount ofvariation in the degree of intimacy based on elapsed time. In thepresent example, t denotes an elapsed time from the time of a previousinteraction, A denotes a coefficient defined in the degree-of-intimacytable, and −tA/2 denotes an amount of variation in the degree ofintimacy with the passage of time (hereinafter, an amount of variationβ). In other words, the longer the time elapsed from the time of aprevious interaction, the greater the decline in both the first andsecond intimacy values. In the present example, it is assumed that t=10(time) and A=0.1. In other words, the amount of variation β in thedegree of intimacy with the passage of time is −tA/2=−0.5.

(3) Calculate First Intimacy Value

Next, α and β described above are added to the first intimacy valuerecorded in the degree-of-intimacy table. Subsequently, the firstintimacy value recorded in the degree-of-intimacy table is updated bythe obtained value. In the present example, 30+5−0.5=34.5 is the latestfirst intimacy value.

(4) Calculate Second Intimacy Value

Next, 1 and β are added to the second intimacy value recorded in thedegree-of-intimacy table. The addition of a value of 1 means that thenumber of interactions has increased by one. Subsequently, the secondintimacy value recorded in the degree-of-intimacy table is updated bythe obtained value. In the present example, 20+1−0.5=20.5 is the latestsecond intimacy value.

-   -   (5) Calculate Sum of Degrees of Intimacy

Finally, the first intimacy value and the second intimacy value areadded up to obtain a total degree of intimacy. In the present example,34.5+20.5=55 is the latest degree of intimacy. In other words, aninteraction by the user with the robot causes the degree of intimacy toincrease from 50 to 55.

<Processing Flow Chart>

Next, specific contents of a process performed by the robot 10 will bedescribed.

First, a process by which the robot 10 and the user interact by voicewill be described with reference to the flow chart shown in FIG. 3.

First, in step S11, the voice input/output unit 11 acquires voice from auser through a microphone 50. The acquired voice is converted into voicedata and transmitted to the voice recognition unit 12.

Next, the voice recognition unit 12 executes voice recognition on theacquired data (step S12). A text representing a result of the voicerecognition is transmitted to the degree-of-intimacy calculating unit 13and the response generating unit 14.

Next, based on the acquired text and the stored degree-of-intimacytable, the degree-of-intimacy calculating unit 13 calculates a degree ofintimacy using the method described earlier (step S13). The calculateddegree of intimacy is transmitted to the response generating unit 14.

Next, the response generating unit 14 generates a response sentencebased on the text output by the voice recognition unit 12 and the degreeof intimacy output by the degree-of-intimacy calculating unit 13 (stepS14). The generated response sentence is transmitted to the controllingunit 15.

In addition, in step S14, the controlling unit 15 performs voicesynthesis based on the response sentence and outputs the synthesizedvoice via the voice input/output unit 11.

As described above, in the first embodiment, an amount of variation ofthe degree of intimacy is calculated and updated based on contents of anutterance made by a user and the number of interactions performed.Accordingly, an effect in which the degree of intimacy varies due to aplurality of contacts can be obtained. In addition, by makingcorrections to the first intimacy value and the second intimacy valuebased on an elapsed time from the time of a last interaction, an effectin which the degree of intimacy declines as time elapses can beobtained. In other words, interactions can be performed in a morehuman-like manner.

Moreover, a degree of decline of the degree of intimacy can be adjustedby a coefficient. Accordingly, a balance can be achieved between anincrease in the degree of intimacy due to performing interactions and adecrease in the degree of intimacy due to the passage of time.

(Second Embodiment)

A second embodiment is an embodiment in which functions of the robotaccording to the first embodiment is distributed between a robot 10 andan interactive server 20.

FIG. 4 is a system configuration diagram of an interaction systemaccording to the second embodiment. Functional blocks having functionssimilar to those of the first embodiment will be denoted by the samereference numerals and a description thereof will be omitted

In the second embodiment, a response by the robot to a user is generatedby the interactive server which includes a communicating unit 21, avoice recognition unit 22 (corresponding to the voice recognition unit12), a degree-of-intimacy calculating unit (corresponding to thedegree-of-intimacy calculating unit 13), and a response generating unit24 (corresponding to the response generating unit 14). The robot 10 andthe interactive server 20 are connected by the communicating unit 21 anda communicating unit 16 to be capable of communicating with each other.For example, a wireless communication network may be used to connect therobot 10 and the interactive server 20 to each other.

In the second embodiment, the robot 10 transmits voice acquired in stepS11 to the interactive server 20 and, in step 312, voice recognition isperformed at the interactive server 20. In addition, the calculation ofa degree of intimacy (step S13) and the generation of a responsesentence (step S14) are executed by the interactive server 20. Thegenerated response sentence is transmitted to the robot 10 and output bysynthesized voice in a similar manner to the first embodiment.

Moreover, while voice synthesis is performed by the robot 10 in thepresent example, alternatively, voice synthesis maybe performed by theinteractive server 20.

(Modification)

The embodiments described above merely represent examples and thepresent invention can be implemented with various modifications withoutdeparting from the spirit and scope of the invention.

For example, while 1 is added to the second intimacy value every timethe number of interactions increases by one in the description of theembodiments, alternatively, a value other than 1 may be added. Inaddition, when contents of an utterance are negative, addition may notbe performed or an arbitrary value may be subtracted.

What is claimed is:
 1. A voice interactive device that interacts with auser by voice, the device comprising: a microphone that acquires a voiceuttered by a user; a processor configured to: recognize the acquiredvoice; calculate a first intimacy value by identifying a keyword in thevoice; calculate a second intimacy value derived from a number ofprevious interactions between the user and the voice interactive device;calculate a degree of intimacy with between the user and the voiceinteractive device using a sum of the first intimacy value and thesecond intimacy value; and generate a response to the recognized voiceusing the degree of intimacy; and a speaker that outputs the response byvoice.
 2. The voice interactive device according to claim 1, furthercomprising: a storage unit that stores the calculated degree ofintimacy, wherein when an utterance is received from the user, theprocessor calculates an amount of variation of the degree of intimacyattributable to the utterance and updates the first intimacy value andthe second intimacy value.
 3. The voice interactive device according toclaim 2, wherein the processor is further configured to identify theuser, and the storage unit stores the degree of intimacy for each of aplurality of users.
 4. The voice interactive device according to claim2, wherein the processor is further configured to correct an amount ofvariation of the first intimacy value or the second intimacy value basedon an elapsed time since last contact with the user.
 5. A voiceinteractive method performed by a voice interactive device interactingwith a user by voice, the voice interaction method comprising: acquiringa voice uttered by a user using a microphone; recognizing the acquiredvoice using a processor; calculating a first intimacy value byidentifying a keyword in the voice, using the processor; calculating asecond intimacy value derived from a number of previous interactionsbetween the user and the voice interactive device, using the processor;calculating a degree of intimacy between the user and the voiceinteractive device using a sum of the first intimacy value and thesecond intimacy value, using the processor; generating a response to therecognized voice using the degree of intimacy, using the processor; andoutputting the response by voice, using a speaker.
 6. An interactionsystem comprising a voice interactive device and an interactive server,the voice interactive device including: a microphone that acquires avoice uttered by a user; a device-side communicator that transmits theacquired voice to the interactive server and acquires a response to theacquired voice from the interactive server; and a speaker that outputsthe response by voice; and the interactive server including: a processorconfigured to: recognize the acquired voice; calculate a first intimacyvalue by identifying a keyword in the voice; calculate a second intimacyvalue derived from a number of previous interactions between the userand the voice interactive device; calculate a degree of intimacy betweenthe user and the voice interactive device using a sum of the firstintimacy value and the second intimacy value; and generate a response tothe recognized voice using the degree of intimacy; and a server-sidecommunicator that transmits the response to the voice interactivedevice.